Wireless power transfer is used to transmit electrical power from a power source to a load with at least part of the conduction path formed over a wireless link (i.e. without wires or conductors). Wireless power transfer could have a variety of uses. For example, one area where wireless power transfer has received a lot of attention is the wireless charging of batteries in mobile communication devices.
To wirelessly transfer power, the power source is provided as part of a transmitter, and the load is provided as part of a receiver. The power can be transmitted to the receiver by radiative or non-radiative means. In non-radiative techniques, the transmitter and receiver are wirelessly coupled (for example, inductive or capacitive coupling). In radiative techniques, the power may be transmitted using, for example, microwaves or lasers.
A number of different standards have been developed to systemize different wireless power transfer systems. For example, the Qi standard has been developed by the Wireless Power Consortium to provide contactless power transfer to a mobile device based on near field magnetic induction between coils. Alternative standards have also been developed by the Alliance for Wireless power and the Power Matters Alliance.